Zephaniah was the great, great grandson of Hezekiah, one of the good kings of Judah. King Josiah, yet another great, great grandson of Hezekiah, was on the throne of Judah when Zephaniah prophesied. At this time, Israel, the northern kingdom, no longer existed. It had been taken into captivity by Assyria one hundred years earlier. Assyria and Egypt battled for control of the world. Located right between both of them, Judah was often territory for battles between the two.
Zephaniah and his fellow prophets - possibly Nahum, Habakkuk, and Jeremiah, all of whom lived in Zephaniah's time - assisted King Josiah in leading a spiritual revolution. He removed idol worship, repaired the temple of God, and brought back worship of the true God. However, most of the people repented only outwardly and when Josiah was killed in battle, they returned to idol worship.